1. Field of the Invention
The invention relates to a vehicle seat that has a head rest.
2. Description of Related Art
A vehicle seat described in Japanese Patent Application Publication No. 2004-017826 (JP 2004-017826 A) includes support brackets, head rest supports and a back receiving member. The support brackets are fixed to a seat back frame. The head rest supports are respectively connected to the support brackets, and a head rest is connected to the upper end portions of the head rest supports. The back receiving member is coupled to the lower end portions of the head rest supports. In the vehicle seat, when the back receiving member is pressed by the back of a seated occupant in the event of a rear-end collision of a vehicle, the head rest supports tilt forward with respect to the support brackets while deforming elastic members provided between the head rest supports and the support brackets. By so doing, the head rest connected to the head rest supports is moved forward, and the head of the seated occupant is received by the head rest so as not to be further moved rearward.
In the thus configured vehicle seat, the head rest moves forward in the event of a rear-end collision of the vehicle. By so doing, it is possible to reduce a period of time (so-called contact time) from occurrence of the rear-end collision to when the head of the passenger contacts the head rest. By so doing, it is possible to improve the whiplash reducing effect of the head rest. However, the large back receiving member and the elastic members are required, so there is still room for improvement in terms of simplification of the configuration.